As a result of the major requirement for mobility and the continuously increasing number of trade goods to be transported, the traffic load and therefore the load on the infrastructure on which the respective type of traffic is based is also increasing in proportion to this. This can be observed in particular in air traffic since, in this case, long distances can be traveled in a relatively short time, as a result of which a significant increase in the amount of traffic, and therefore an increased traffic load, is predicted with respect to the globalization for the future. Similar developments are in this case also expected in the maritime field.
These traffic areas in particular, such as the maritime field or aviation, are characterized by their high freedom of movement while traveling. For example, the entire three-dimensional flight space is available to an aircraft, as a result of which the number of possible transport paths between two points is virtually infinite. These traffic areas are therefore fundamentally distinguished from other traffic areas, such as roads or rails, while the transport paths or routes are predetermined by the infrastructure itself.
In order to ensure safe flight traffic for the large number of annual flight movements, the freedom of movement which is predetermined by the air space infrastructure is highly regimented by air traffic control. Aircraft fly only within fixed predetermined corridors, with their flight route being defined and fixed. This flight route is in this case also referred to as a trajectory, which indicates the spatial position of the aircraft at different times. In other words, a trajectory contains a series of waypoints which the vehicle must reach at a specific time. If the aircraft is now guided on a four-dimensional trajectory such as this from its take-off airport to its destination airport, and it may deviate from this predetermined trajectory only in the event of danger or in response to instructions from air traffic control.
These four-dimensional predetermined trajectories on which the aircraft must move are intended to prevent aircraft from colliding with one another, with this risk being particularly high near airports. In this case, a hazard or conflict situation does not exist only when the aircraft would actually collide with one another, but even when they fly past one another, relatively close to one another. For example, vortices can contribute to aircraft crashing, even though they have not collided with one another. In order to prevent this, the aircraft must always be separated from one another by a minimum distance as they travel through the traffic area. A conflict situation arises if this minimum separation is not maintained.
By way of example, U.S. Pat. No. 6,421,603 B1 discloses a method by means of which a conflict situation between an aircraft and the terrain over which the aircraft is flying is intended to be identified. For this purpose, a terrain database is created, and contains a maximum and a minimum altitude with respect to relatively large regions. If the trajectory to be flown by the aircraft is now within this region, then the region is further subdivided into smaller regions when the trajectory is below the maximum altitude in that region. Therefore, in the end, the only subregions which are compared with the trajectory are those which are actually also classified as being critical. Furthermore, this document describes how a conflict situation can also be identified by moving severe weather, in that every trajectory segment of the severe weather is compared with each trajectory segment of the aircraft, and a check is carried out to determine whether they overlap in space or time.
One disadvantage in this case, in particular, is the fact that the calculation complexity for trajectory comparison is very high (exponential) because every trajectory segment must be compared with every other trajectory segment of other objects. When there are a large number of objects, this easily results in a level of computation complexity which can no longer be carried out in an adequate time. This is particularly critical when the aim is to monitor air traffic globally.